Using Sensor Data to Identify Factors Affecting Internal Air Quality within 279 Lower Income Households in Cornwall, South West of England.

(1) Background: Poor air quality affects health and causes premature death and disease. Outdoor air quality has received significant attention, but there has been less focus on indoor air quality and what drives levels of diverse pollutants in the home, such as particulate matter, and the impact this has on health; (2) Methods: This study conducts analysis of cross-sectional data from the Smartline project. Analyses of data from 279 social housing properties with indoor sensor data were used to assess multiple factors that could impact levels of particulate matter. T-Tests and Anova tests were used to explore associations between elevated PM2.5 and building, household and smoking and vaping characteristics. Binary logistic regression was used to test the association between elevated particulate matter and self-reported health; (3) Results: Of the multiple potential drivers of the particulate matter investigated, smoking and vaping were significantly associated with mean PM2.5. Following multivariate analysis, only smoking remained significantly associated with higher mean concentrations. Properties in which <15 cigarettes/day were smoked were predicted to have PM2.5 concentrations 9.06 µg/m3 higher (95% CI 6.4, 12.82, p ≤ 0.001) than those in which residents were non-smokers and 11.82 µg/m3 higher (95% CI 7.67, 18.19, p ≤ 0.001) where >15 cigarettes were smoked; (4) Conclusions: A total of 25% of social housing properties in this study experienced levels of indoor PM greater than WHO guideline levels for ambient air pollution. Although there are many factors that impact air quality, in this study the main driver was smoking. This highlights the importance of targeting smoking in indoor environments in future smoking cessation and control policy and practice and of understanding how pollutants interact in the home environment. There is also a need for further research into the impact on indoor air quality of vaping, particularly due to the rise in use and uncertainty of its long-term impact.

UK Internet antenatal dietary advice: a content accuracy and readability analysis.

The aim of the study was to assess the accuracy and readability of Internet prenatal nutrition advice. Between August and December 2018, 130 Internet pages returned from Google searches on foods to avoid, foods to eat and supplements use were compared with UK government advice for pregnant women. Readability was assessed using the Flesch Readability Ease (FRE) tool. Descriptive and non-parametric tests were used. Spearman's correlation explored associations between accuracy and readability. Kruskal-Wallis tests with Bonferroni correction were used for multiple pairwise tests and Mann-Whitney U tests for two-sample differences in medians. A total of 130 Internet pages were examined: 48 % from publishers, 27 % from other commercial organisations, 22 % from charities and 3 % from governments. Eighty-three (64 %) pages contained inaccurate and accurate advice, twenty-three (18 %) were accurate and complete, twenty-one (16 %) were inaccurate, and three (2 %) lacked any relevant advice. The median percentage accuracy of all advice was 83 (lower quartile, upper quartile: 48, 100). Median FRE was 55 (46, 61) 'fairly difficult'. Eighty-seven pages (67 %) scored below the recommended FRE for public Internet pages. There was a weak positive correlation between accuracy and readability of Internet pages (rho = 0·241, P = 0·006). Accuracy of Internet pages did not differ by dietary theme. Pages on supplements were the most difficult to read. Internet pages from publishers and other commercial organisations were significantly less accurate than those from not-for-profit organisations (median percentage difference -8 (-29, 0·00), P = 0·019). Much pregnancy-related dietary advice online is inaccurate and difficult to read. Advice should be developed in consultation with qualified nutritionists and dietitians.

Effect of combining multiple micronutrients with iron supplementation on Hb response in children: systematic review of randomized controlled trials.

OBJECTIVES: To study the effect of combining multiple (two or more) micronutrients with Fe supplementation on Hb response, when compared with placebo and with Fe supplementation, in children. DATA SOURCES: Electronic databases, personal files, hand search of reviews, bibliographies of books, and abstracts and proceedings of international conferences. REVIEW METHODS: Randomized controlled trials evaluating change in Hb levels with interventions that included Fe and multiple-micronutrient supplementation in comparison to placebo alone or Fe alone were analysed in two systematic reviews. RESULTS: Twenty-five trials were included in the review comparing Fe and micronutrient supplementation with placebo. The pooled estimate (random effects model) for change in Hb with Fe and micronutrient supplementation (weighted mean difference) was 0.65 g/dl (95 % CI 0.50, 0.80, P < 0.001). Lower baseline Hb, lower height-for-age Z score, non-intake of 'other micronutrients' and malarial non-hyperendemic region were significant predictors of greater Hb response and heterogeneity. Thirteen trials were included in the review comparing Fe and micronutrient supplementation with Fe alone. The pooled estimate for change in Hb with Fe and micronutrient supplementation (weighted mean difference) was 0.14 g/dl (95 % CI 0.00, 0.28, P = 0.04). None of the variables were found to be significant predictors of Hb response. CONCLUSIONS: Synthesized evidence indicates that addition of multiple micronutrients to Fe supplementation may only marginally improve Hb response compared with Fe supplementation alone. However, addition of 'other micronutrients' may have a negative effect. Routine addition of unselected multiple micronutrients to Fe therefore appears unjustified for nutritional anaemia control programmes.

Potential impacts of iron biofortification in India.

Iron deficiency is a widespread nutrition and health problem in developing countries, causing impairments in physical activity and cognitive development, as well as maternal mortality. Although food fortification and supplementation programmes have been effective in some countries, their overall success remains limited. Biofortification, that is, breeding food crops for higher micronutrient content, is a relatively new approach, which has been gaining international attention recently. We propose a methodology for ex ante impact assessment of iron biofortification, building on a disability-adjusted life years (DALYs) framework. This methodology is applied in an Indian context. Using a large and representative data set of household food consumption, the likely effects of iron-rich rice and wheat varieties are simulated for different target groups and regions. These varieties, which are being developed by an international public research consortium, based on conventional breeding techniques, might be ready for local distribution within the next couple of years. The results indicate sizeable potential health benefits. Depending on the underlying assumptions, the disease burden associated with iron deficiency could be reduced by 19-58%. Due to the relatively low institutional cost to reach the target population, the expected cost-effectiveness of iron biofortification compares favourably with other micronutrient interventions. Nonetheless, biofortification should not be seen as a substitute for other interventions. Each approach has its particular strengths, so they complement one another.

Estimating the global costs of vitamin A capsule supplementation: a review of the literature.

BACKGROUND: Vitamin A supplementation reduces child mortality. It is estimated that 500 million vitamin A capsules are distributed annually. Policy recommendations have assumed that the supplementation programs offer a proven technology at a relatively low cost of around US$0.10 per capsule. OBJECTIVES: To review data on costs of vitamin A supplementation to analyze the key factors that determine program costs, and to attempt to model these costs as a function of per capita income figures. METHODS: Using data from detailed cost studies in seven countries, this study generated comparable cost categories for analysis, and then used the correlation between national incomes and wage rates to postulate a simple model where costs of vitamin A supplementation are regressed on per capita incomes. RESULTS: Costs vary substantially by country and depend principally on the cost of labor, which is highly correlated with per capita income. Two other factors driving costs are whether the program is implemented in conjunction with other health programs, such as National Immunization Days (which lowers costs), and coverage in rural areas (which increases costs). Labor accounts for 70% of total costs, both for paid staff and for volunteers, while the capsules account for less than 5%. Marketing, training, and administration account for the remaining 25%. CONCLUSIONS: Total costs are lowest (roughly US$0.50 per capsule) in Africa, where wages and incomes are lowest, US$1 in developing countries in Asia, and US$1.50 in Latin America. Overall, this study derives a much higher global estimate of costs of around US$1 per capsule.

Effect of iron supplementation on haemoglobin response in children: systematic review of randomised controlled trials.

OBJECTIVE: To evaluate the effect of iron supplementation on haemoglobin (Hb) in children through a systematic review of randomised controlled trials. MATERIALS AND METHODS: Electronic databases, personal files, hand search of reviews, bibliographies of books, and abstracts and proceedings of international conferences were reviewed. Randomised controlled trials evaluating change in Hb levels with interventions that included oral or parenteral iron supplementation or iron-fortified formula milk or cereals were analysed. RESULTS: A total of 55 trials (56 cohorts) provided relevant information. Publication bias was evident (P < 0.001). The pooled estimate (random-effects model) for change in Hb with iron supplementation (weighted mean difference) was 0.74 g/dL (95% CI, 0.61-0.87; P < 0.001; P < 0.001 for heterogeneity). Lower baseline Hb level, oral medicinal iron supplementation, and malarial nonhyperendemic region were significant predictors of greater Hb response and heterogeneity. Projections suggested that, on average, between 37.9% and 62.3% of baseline anaemia (Hb <11 g/dL) was responsive to iron supplementation among children under 6 years of age; the corresponding range for malarial hyperendemic regions was 5.8% to 31.8%. CONCLUSIONS: This systematic review indicates that iron supplementation increases Hb levels in children significantly but modestly. The increase is greater in subjects who are anaemic at the start of the trial and lower in malarial hyperendemic areas and in those consuming iron-fortified food. The projected reductions in prevalence of anaemia with iron supplementation alone highlight the need for additional area-specific interventions, particularly in malaria-prone regions.

Plant breeding to control zinc deficiency in India: how cost-effective is biofortification?

OBJECTIVE: To estimate the potential impact of zinc biofortification of rice and wheat on public health in India and to evaluate its cost-effectiveness compared with alternative interventions and international standards. DESIGN: The burden of zinc deficiency (ZnD) in India was expressed in disability-adjusted life years (DALYs) lost. Current zinc intakes were derived from a nationally representative household food consumption survey (30-day recall) and attributed to household members based on adult equivalent weights. Using a dose-response function, projected increased zinc intakes from biofortified rice and wheat were translated into potential health improvements for pessimistic and optimistic scenarios. After estimating the costs of developing and disseminating the new varieties, the cost-effectiveness of zinc biofortification was calculated for both scenarios and compared with alternative micronutrient interventions and international reference standards. SETTING: India. SUBJECTS: Representative household survey (n = 119 554). RESULTS: The calculated annual burden of ZnD in India is 2.8 million DALYs lost. Zinc biofortification of rice and wheat may reduce this burden by 20-51% and save 0.6-1.4 million DALYs each year, depending on the scenario. The cost for saving one DALY amounts to $US 0.73-7.31, which is very cost-effective by standards of the World Bank and the World Health Organization, and is lower than that of most other micronutrient interventions. CONCLUSIONS: Not only may zinc biofortification save lives and prevent morbidity among millions of people, it may also help accommodate the need to economise and to allocate resources more efficiently. Further research is needed to corroborate these findings.

Meeting report on the 3rd International Congress on Developmental Origins of Health and Disease (DOHaD).

Developmental origins of health and disease (DOHaD) focuses on the earliest stages of human development, and provides a novel paradigm to complement other strategies for lifelong prevention of common chronic health conditions. The 3 International Congress on DOHaD, held in 2005, retained the most popular features from the first two biannual Congresses, while adding a number of innovations, including increased emphasis on implications of DOHaD for the developing world; programs for trainees and young investigators; and new perspectives, including developmental plasticity, influences of social hierarchies, effects of prematurity, and populations in transition. Emerging areas of science included, first, the controversial role of infant weight gain in predicting adult obesity, diabetes, and cardiovascular disease. Second, in the era of epidemic obesity, paying attention to the over-nourished fetus is as important as investigating the growth retarded one. Third, environmental toxins appear to have abroad range of long-lasting effects on the developing human. Fourth, epigenetic mechanisms could unite several strands of human and animal observations, and explain how genetically identical individuals raised in similar postnatal environments can nonetheless develop widely differing phenotypes. Improving the environment to which an individual is exposed during development may be as important as any other public health effort to enhance population health world wide.

Effect of iron supplementation on physical performance in children and adolescents: systematic review of randomized controlled trials.

OBJECTIVE: To evaluate the effect of iron supplementation on physical performance in children (0-18 years) through systematic review of randomised controlled trials (RCTs). DATA SOURCES: Electronic databases, personal files, handsearch of reviews, bibliographies of books, abstracts and proceedings of international conferences. REVIEW METHODS: RCTs with interventions that included oral or parenteral iron supplementation, fortified formula milk, or cereals were evaluated. The physical performance outcomes studied were heart rate, treadmill endurance times, blood lactate, and oxygen consumption. RESULTS: A total of three studies were included, in all of which iron was supplemented in the form of oral medicinal iron. At 5, 6 and 7 miles per hour running speeds, the pooled weighted mean (95% Cl) difference (WMD) in the heart rate (per minute) between the iron and the placebo, following exercise was -7.3 (-19.6, 4.9; p = 0.241), -6.6 (- 19.9, 6.6; p = 0.327), and -8.0 (-19.7, 3.7; p = 0.182), respectively. After excluding the study with nonanemic subjects, the corresponding figures were -13.1 (-23.2, -3.1; p= 0.01), -14.2 (-22.3, -6.1; p = 0.001) and -12.7 (-23.5, 1.9; p = 0.021), respectively. Oxygen consumption, estimated in two studies, showed no significant difference between the treatment groups. Blood lactate levels were estimated in one study only at two different doses of iron, and were significantly lower (p < 0.05) in iron supplemented group in comparison to placebo both before (7.71 and 7.55 mg/dL versus 8.43 mg/dL) and after (14.36 and 14.35 mg/dL versus 16.48 mg/dL) exercise. Treadmill endurance time was significantly better in iron supplemented group when compared with placebo in one study. CONCLUSIONS: Iron supplementation may have a positive effect on the physical performance of children, as evaluated through the post exercise heart rate in anemic subjects, blood lactate levels and treadmill endurance time. In view of the limited data availability, this finding cannot be considered conclusive.

Effect of iron supplementation on physical growth in children: systematic review of randomised controlled trials.

OBJECTIVE: To evaluate the effect of iron supplementation on physical growth in children through a systematic review of randomised controlled trials (RCTs). DATA SOURCES: Electronic databases, personal files, and hand search of reviews, bibliographies of books, abstracts and proceedings of international conferences. REVIEW METHODS: RCTs evaluating change in anthropometry with interventions that included oral or parenteral iron supplementation, or iron-fortified formula milk or cereals, were analysed. RESULTS: Twenty-five trials (26 cohorts) had relevant information. There was no evidence of publication bias. The pooled estimates (random effects model) did not document a statistically significant (P>0.05) positive effect of iron supplementation on any anthropometric variable (weight-for-age, weight-for-height, height-for-age, mid upper-arm circumference, skinfold thickness, head circumference). Significant heterogeneity was evident, and its predictors included greater weight-for-age in supplemented children in malaria hyperendemic regions and greater weight-for-height for children above 5 years of age, but a negative effect on linear growth in developed countries and with supplementation for 6 months or longer. CONCLUSIONS: This review did not document a positive effect of iron supplementation on the physical growth of children. The identified predictors of heterogeneity should be considered as exploratory and requiring confirmation, not conclusive.

Biofortification of staple food crops.

Deficiencies of vitamin A, iron, and zinc affect over one-half of the world's population. Progress has been made to control micronutrient deficiencies through supplementation and food fortification, but new approaches are needed, especially to reach the rural poor. Biofortification (enriching the nutrition contribution of staple crops through plant breeding) is one option. Scientific evidence shows this is technically feasible without compromising agronomic productivity. Predictive cost-benefit analyses also support biofortification as being important in the armamentarium for controlling micronutrient deficiencies. The challenge is to get producers and consumers to accept biofortified crops and increase their intake of the target nutrients. With the advent of good seed systems, the development of markets and products, and demand creation, this can be achieved.

Stable isotope dilution techniques for assessing vitamin A status and bioefficacy of provitamin A carotenoids in humans.

Vitamin A deficiency is a major global public health problem. Among the variety of techniques that are available for assessing human vitamin A status, evaluating the provitamin A nutritional values of foodstuffs and estimating human vitamin A requirements, isotope dilution provides the most accurate estimates. Although the relative expense of isotope dilution restricts its applications, it has an important function as the standard of reference for other techniques. Mathematical modelling plays an indispensable role in the interpretation of isotope dilution data. This review summarises recent applications of stable isotope methodology to determine human vitamin A status, estimate human vitamin A requirements, and calculate the bioconversion and bioefficacy of food carotenoids.

Beta-carotene-rich orange-fleshed sweet potato improves the vitamin A status of primary school children assessed with the modified-relative-dose-response test.

BACKGROUND: Beta-carotene-rich orange-fleshed sweet potato (OFSP) is an excellent source of provitamin A. In many developing countries, sweet potato is a secondary staple food and may play a role in controlling vitamin A deficiency. OBJECTIVE: The objective was to determine the efficacy of daily consumption of boiled and mashed OFSP in improving the vitamin A status of primary school children. DESIGN: Children aged 5-10 y were randomly assigned to 2 groups. The treatment group (n = 90) consumed 125 g boiled and mashed OFSP (1031 retinol activity equivalents/d as beta-carotene), and the control group (n = 90) consumed an equal amount of white-fleshed sweet potato devoid of beta-carotene for 53 school days. All children were dewormed to exclude helminthic infection. The modified-relative-dose-response test for vitamin A status was conducted before and after intervention. RESULTS: The estimated intervention effect for the ratio of 3,4-didehydroretinol to retinol (DR:R) was -0.008 (95% CI: -0.015, -0.001; P = 0.0203), which indicated a greater improvement in vitamin A liver stores in the treatment group than in the control group. The proportions of children with normal vitamin A status (DR:R < 0.060) in the treatment group tended to increase from 78% to 87% (P = 0.096) and did not change significantly (from 86% to 82%) in the control group (P = 0.267). These proportions were not used to test the intervention effect or within-group changes because the study was powered to test the intervention effect on DR:R. CONCLUSIONS: Consumption of OFSP improves vitamin A status and can play a significant role in developing countries as a viable long-term food-based strategy for controlling vitamin A deficiency in children.

Effect of iron supplementation on mental and motor development in children: systematic review of randomised controlled trials.

OBJECTIVE: To evaluate the effect of iron supplementation on mental and motor development in children through a systematic review of randomised controlled trials (RCTs). DATA SOURCES: Electronic databases, personal files, hand search of reviews, bibliographies of books, abstracts and proceedings of international conferences. REVIEW METHODS: RCTs with interventions that included oral or parenteral iron supplementation, fortified formula milk or cereals were evaluated. The outcomes studied were mental and motor development scores and various individual development tests employed, including Bayley mental and psychomotor development indices and intelligence quotient. RESULTS: The pooled estimate (random effects model) of mental development score standardised mean difference (SMD) was 0.30 (95% confidence interval (CI) 0.15 to 0.46, P<0.001; P<0.001 for heterogeneity). Initial anaemia and iron-deficiency anaemia were significant explanatory variables for heterogeneity. The pooled estimate of Bayley Mental Development Index (weighted mean difference) in younger children (<27 months old) was 0.95 (95% CI -0.56 to 2.46, P=0.22; P=0.016 for heterogeneity). For intelligence quotient scores (> or =8 years age), the pooled SMD was 0.41 (95% CI 0.20 to 0.62, P<0.001; P=0.07 for heterogeneity). There was no effect of iron supplementation on motor development score (SMD 0.09, 95% CI -0.08 to 0.26, P=0.28; P=0.028 for heterogeneity). CONCLUSIONS: Iron supplementation improves mental development score modestly. This effect is particularly apparent for intelligence tests above 7 years of age and in initially anaemic or iron-deficient anaemic subjects. There is no convincing evidence that iron treatment has an effect on mental development in children below 27 months of age or on motor development.

The usefulness of in vitro models to predict the bioavailability of iron and zinc: a consensus statement from the HarvestPlus expert consultation.

A combination of dietary and host-related factors determines iron and zinc absorption, and several in vitro methods have been developed as preliminary screening tools for assessing bioavailability. An expert committee has reviewed evidence for their usefulness and reached a consensus. Dialyzability (with and without simulated digestion) gives some useful information but cannot predict the correct magnitude of response and may sometimes predict the wrong direction of response. Caco-2 cell systems (with and without simulated digestion) have been developed for iron availability, but the magnitude of different effects does not always agree with results obtained in human volunteers, and the data for zinc are too limited to draw conclusions about the validity of the method. Caco-2 methodologies vary significantly between laboratories and require experienced technicians and good quality cell culture facilities to obtain reproducible results. Algorithms can provide semi-quantitative information enabling diets to be classified as high, moderate, or low bioavailability. While in vitro methods can be used to generate ideas and develop hypotheses, they cannot be used alone for important decisions concerning food fortification policy, selection of varieties for plant breeding programs, or for new product development in the food industry. Ultimately human studies are required for such determinations.

Report on the 2nd World Congress on Fetal Origins of Adult Disease, Brighton, U.K., June 7-10, 2003.

In 1989, reports suggested that the fetal environment, as reflected in birth size, was related to the risk of noncommunicable diseases in adult life. This association was first described for coronary heart disease but rapidly extended to include type 2 diabetes, osteoporosis, and metabolic and endocrine homeostasis. This led to the development of the fetal origins of adult disease paradigm, which resulted in a refocusing of research effort over the next 10 y to consider the lifelong consequences of perinatal influences on chronic diseases. Previously, perinatal influences had largely been seen in terms of teratogenic effects or acute birth injury rather than whether trajectories and responses made during early development had lifelong consequences. Indeed, in developmental biology, it is widely recognized that adaptive plastic responses during early development often have consequences for function in later adulthood. Although the relative importance of this newly recognized set of phenomena to the burden of human disease has been controversial, the research precipitated by those early observations has confirmed their robustness and started to provide a mechanistic basis to this biology. Two world congresses have been held to review progress in this research. Both have been characterized by a unique multidisciplinary attendance ranging from molecular, experimental, and developmental biologists to epidemiologists and health economists.

Titers of antibody to common pathogens: relation to food-based interventions in rural Kenyan schoolchildren.

BACKGROUND: Undernutrition is widely perceived to affect the development of an effective immune system. OBJECTIVE: We used a mini-analysis system to quantitate antibody titers and evaluate the sera of 200 Kenyan schoolchildren for antibodies to Helicobacter pylori [isotypes of immunoglobulins A (IgA), G (IgG), and M (IgM)], hepatitis A virus, rotavirus, tetanus toxoid (IgG), and a panel of recombinant malarial antigens (MSP1(19), MSP2, Ag512, MSP4, and MSP5). DESIGN: Children participated in a school-based feeding intervention with meat, milk, or nonanimal-source foods or in a nonintervention control group. Microvolumes (200 mL) of sera were analyzed at baseline and after 1 y. RESULTS: Nearly all children had elevated titers of antibody to H. pylori, hepatitis A virus, rotavirus, and malaria at the outset, despite a high prevalence of apparent biochemical micronutrient deficiencies and stunting, but many had titers of tetanus toxoid IgG antibodies below the protective concentration. Children with low hemoglobin had a greater proportion of elevated H. pylori IgM antibody titers at baseline, which suggests that current infection with H. pylori may be associated with anemia. Compared with the control subjects, only the group eating meat had a significant increase in H. pylori IgM antibodies during the intervention (P = 0.019). No other group comparisons with the control subjects were statistically significant. The additional finding that the sera of some children showed inadequate tetanus-protective antibodies, despite immunization, suggests that the vaccination program was suboptimal. CONCLUSIONS: A large battery of immune assays can be performed on microvolumes of sera. Furthermore, despite evidence of malnutrition, children do develop significant antibody-mediated responses to common pathogens.

Defining nutritional status of women in developing countries.

OBJECTIVE: To define a de facto reference body mass index (BMI) for women in developing countries and compare its performance with the Quetelet BMI. DESIGN: A logarithmic equation for elite wt/ht references was developed using the weight (wt) and height (ht) of 10,524 non-pregnant elite mothers. Functional outcomes were compared using both BMIs. SETTING: Forty-six national surveys from 36 developing countries. SUBJECTS: Mothers 15-49 years old. RESULTS: The defacto reference standard deviation showed 2.2% of elite women were undernourished and 6.3% overnourished; lower and upper limits for 'ideal' wt/ht were 73% and 137%, respectively. Compared with the age-based and medium frame standards of the First and Second National Health and Nutrition Examination Surveys (NHANES I & II), the defacto reference defined fewer women as undernourished (5.3% vs. 10.5% and 14.4%, respectively), but more as overnourished (20.4% vs. 13.7% and 15.9%, respectively). In the de facto reference, BMI = wt/ht(1.6). Using the age-based and medium-frame-based Quetelet BMI (wt/ht2), 28.5% and 31.7% had a low and 13.0% and 14.7% a high BMI, respectively. For the defacto reference, 18.4% of the elite mothers had a low BMI and 19.3% a high BMI. Applying the de facto reference to all women showed that the distribution of BMI was similar irrespective of the reference used. Functional outcomes were similar for both BMIs. CONCLUSIONS: The NHANES I & II growth curves define more women as overnourished than the de facto curve, but the opposite for defining the undernourished. Functional outcomes were similar for both BMIs, suggesting there is no great advantage to using a defacto BMI based on national-level data from these 46 national surveys.